JP6238780B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus using an electrophotographic system, such as a copying machine, a printer, a facsimile machine, or the like, equipped with a removable cartridge.

  2. Description of the Related Art Conventionally, an image forming apparatus using an electrophotographic system is a process cartridge in which a photosensitive drum that is an image carrier and a process unit that acts on the photosensitive drum are integrated into a cartridge, and the cartridge is detachable from the image forming apparatus. The method is adopted.

  2. Description of the Related Art In recent years, when an image forming apparatus is transported, there is an increasing number of cartridge-enclosed transport modes in which a process cartridge is transported in a state where it is packaged in the apparatus main body of the image forming apparatus for the purpose of improving transport efficiency.

  At that time, if the image forming apparatus is transported while the photosensitive drum on the cartridge side and the transfer roller on the apparatus main body side are in contact with each other, a concave portion is formed on the transfer roller and an image defect occurs. For this reason, many devices are used that transport the photosensitive drum and the transfer roller separated from each other by using a dedicated separating member that separates the photosensitive drum and the transfer roller.

  In Patent Document 1, a switching member for determining the position of the drum protection member is provided in the process cartridge, and the configuration is switched to a transport mode in which the photosensitive drum and the transfer roller are separated from each other and a usage mode during printing operation.

Japanese Patent Laid-Open No. 11-184351

  In Patent Document 1, when the user uses the image forming apparatus for the first time, it is necessary to switch the switching member of the process cartridge from the transport form to the use form. For this reason, there is a possibility that the user forgets to switch the switching member to the position of the use form and erroneously inserts the process cartridge in the transport form.

  Further, when the photosensitive drum and the transfer roller are separated using a dedicated separation member, it is necessary to remove the separation member before using the image forming apparatus.

  In view of this, there has been a demand for an image forming apparatus that is simplified and more excellent in operability. An object of the present invention is to provide an image forming apparatus that meets this demand.

In order to achieve the above object, a typical configuration of an image forming apparatus according to the present invention is such that a cartridge having at least an image carrier on which a toner image is formed is detachable from the apparatus main body and forms an image on a recording material. The image forming apparatus includes a cartridge mounting portion on which the cartridge is detachably mounted, and a nip portion that contacts the image carrier and transfers a toner image formed on the image carrier to a recording material. A transfer device ; a transport mechanism that transports the recording material to the nip portion; and a movable guide member that guides the recording material to the downstream side in the transport direction. a first position for separating the image bearing member when inserted into the mounting portion and the said transfer device, and the image bearing member when said cartridge is inserted into the cartridge mounting portion A serial transfer system is allowed to contact, and a second position for guiding the recording material to the downstream side, there is may take, the guide member is in said first position In this case, the transfer device is covered between the transfer device and the cartridge .

  According to the present invention, it is possible to provide an image forming apparatus with simplified apparatus and more excellent operability.

The figure explaining the movement of the conveyance guide plate in Example 1. The figure explaining the movement of a conveyance guide board similarly FIG. 7 is an overhead view of a registration roller pair and a transfer roller portion in the image forming apparatus of FIG. Illustration of the same part FIG. 3 is an overhead view showing a state where the conveyance guide plate located at the second position in FIG. 3 has been moved to the first position. Illustration of the same part Schematic diagram of a vertical right side view of an image forming apparatus in Embodiment 1. The figure which shows the storing state of the manual feed tray Process cartridge illustration Process cartridge installation / removal instructions Figure showing the open state of the door External perspective view of process cartridge Block diagram of control system Illustration of forming the transfer nip FIG. 6 is a diagram for explaining the movement of the conveyance guide plate in the second embodiment. The figure explaining the movement of a conveyance guide board similarly

  The best mode for carrying out the present invention will be exemplarily described in detail below based on the embodiments with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. .

[Example 1]
(Overall configuration of image forming apparatus)
FIG. 7 is a schematic right side view of the longitudinal section of the process cartridge type image forming apparatus 100 in this embodiment. In this image forming apparatus 100, an electrophotographic laser beam printer (removable) is used in which a process cartridge 30 is detachably mounted (detachable) on a cartridge mounting portion 100B of an image forming apparatus main body (hereinafter referred to as an apparatus main body) 100A. An electrophotographic image forming apparatus).

  That is, referring to FIG. 13, a toner image corresponding to electrical image information input from an external host device 200 such as a personal computer, an image reader, or a facsimile to a control board (control circuit unit) 15a of the electrical component 15 is recorded on the recording material P. And can be printed out. The electrical unit 15 includes a power supply unit 15 b of the image forming apparatus 100 and a control board 15 a that controls the image forming apparatus 100. The recording material P is a sheet-like member on which a toner image is formed by the image forming apparatus 100. For example, regular or irregular plain paper, thick paper, thin paper, envelope, postcard, seal, resin sheet, OHP sheet, glossy paper Etc. are included.

  Here, in the following description, the front side (front side) of the image forming apparatus 100 is the side on which the opening / closing door (cartridge cover) 27 is provided. The back side (rear side) is the opposite side to the front side. Left and right are left or right when the image forming apparatus 100 is viewed from the front side. Up and down are up or down in the direction of gravity. Further, the rotational axis direction of an electrophotographic photosensitive drum (hereinafter referred to as a photosensitive drum) 10 as an image carrier is defined as a longitudinal direction. In addition, the side where the photosensitive drum 10 receives driving force from the apparatus main body 100A in the longitudinal direction (right side in this embodiment) is a driving side, and the opposite side (left side) is a non-driving side.

  A schematic configuration of the image forming apparatus 100 in FIG. 7 will be described along the flow of the recording material (recording medium) P. The recording material P is conveyed to the image forming means 2 by the feeding and conveying means 1 to transfer the toner image, and then the recording material P is conveyed to the fixing device (fixing means) 3 to fix the toner image, and then the discharge section. 4 is discharged.

  More specifically, a cassette 5 constituting a part of the feeding / conveying means 1 is loaded in the lower part of the image forming apparatus 100. A recording material P is loaded and stored in the cassette 5. The recording material P in the cassette 5 is sequentially fed from the uppermost recording material P by the feeding roller 6 that rotates counterclockwise, and is sent to the image forming means 2 by the conveying roller pair 7 and the registration roller pair 8. .

The image forming unit 2 includes a process cartridge (hereinafter referred to as a cartridge) 30 mounted on a cartridge mounting unit 100B of the apparatus main body 100A, a laser scanner 9 as an exposure unit, a transfer roller 11 as a transfer unit (transfer device) , and the like. It is configured. In this embodiment, the cartridge 30 includes a photosensitive drum 10 and a charging means 31, a developing means 32, and a cleaning means 33 as an image forming process means (image forming process apparatus) acting on the photosensitive drum 10 as a cartridge frame. 34 is integrated into a cartridge.

  The charging means 31 is a device that uniformly charges the outer peripheral surface of the photosensitive drum 10 to a predetermined polarity and potential, and is a charging roller in this embodiment. The developing means 32 is a device that develops the electrostatic latent image formed on the surface of the photosensitive drum 10 as a toner image with a developer (toner). The cleaning means 33 is a device that removes residues such as transfer residual toner from the surface of the photosensitive drum after the toner image is transferred to the recording material P, and cleans the surface of the photosensitive drum. In this embodiment, the cleaning means 33 is a blade cleaning device.

  The laser beam L corresponding to the image information is rotationally driven by the laser scanner 9 in a clockwise direction at a predetermined peripheral speed (process speed), and is irradiated onto the photosensitive drum 10 charged by the charging roller 31 to be irradiated with the photosensitive drum 10. An electrostatic latent image is formed thereon. The laser beam L is irradiated from the laser scanner 9 to the photosensitive drum 10 through a slit-like window hole 35 formed on the upper surface of the cartridge frame 34. The electrostatic latent image is developed as a toner image by the developing device 32.

A transfer roller 11 is brought into contact with the lower surface of the photosensitive drum 10 with a predetermined pressing force to form a transfer nip portion. As described above, the recording material P conveyed by the feeding / conveying means 1 is introduced into the transfer nip portion at a predetermined control timing by the registration roller pair 8 and is nipped and conveyed. A transfer bias is applied. As a result, the toner image on the photosensitive drum 10 side is sequentially transferred onto the surface of the recording material P in the transfer nip portion. In the present embodiment, the registration roller pair 8 is a conveying means (conveying mechanism) for conveying the recording material P to the transfer nip portion.

  The recording material P that has exited the transfer nip portion is sequentially separated from the surface of the photosensitive drum 10, passed through the conveyance guide 12, and introduced into the fixing device 3, and is sandwiched by the fixing nip portion formed by the fixing member and the pressure member. Be transported. As a result, the unfixed toner image on the recording material P is fixed as a fixed image. When the single-sided recording mode is selected, the recording material P that has passed through the fixing nip is transported by the transport roller pair 13 and the discharge transport roller pair 14 and discharged to the discharge unit 4 at the upper part of the apparatus as a single-side recorded product. Is done. The surface of the photosensitive drum 10 after separation of the recording material is cleaned by the cleaning device 33 and repeatedly used for image formation.

  When the front / back double-sided recording mode is selected, the recording material P that has passed through the fixing device 3 and has been image-recorded on the front side (one side) is switchback conveyed by the reverse rotation driving of the discharge conveying roller pair 14. Further, the recording material P is transported back to the transport roller pair 7 again by the transport roller pairs 16 and 17, and is introduced into the transfer nip portion of the image forming means 2 in a state where the front and back are reversed by the registration roller pair 8 at a predetermined control timing. The As a result, the toner image is transferred to the back side (the other side) of the recording material P.

  Thereafter, as in the single-sided recording mode, the recording material P is transported by the fixing device 3, the transport roller pair 13, and the discharge transport roller pair 14, and is discharged to the discharge unit 4 as a front and back double-side recorded matter.

  Further, in the image forming apparatus 100 of the present embodiment, a manual feed tray 18 as a manual feed unit for the recording material P is disposed outside the opening / closing door 27 on the front side. The manual feed tray 18 is folded and stored with respect to the open / close door 27 as shown in FIG. 8 when not in use. In the case of feeding the recording material using the manual feed tray 18, as shown in FIG. 7, the manual feed tray 18 is unfolded from the outer surface of the opening / closing door 27 to the front side, and the recording material P is stacked.

  The recording material P loaded on the manual feed tray 18 is sequentially fed out from the uppermost recording material P by a manual feed roller 20 that rotates in the clockwise direction, and the registration roller pair 8 of the image forming unit 2 has a predetermined control timing. It is sent to the transfer nip. Thus, image formation is performed on the manually fed recording material P.

  Reference numerals 24 and 25 denote a top sensor flag (detection flag) and a photo sensor (detection sensor) which are arranged in the recording material conveyance direction upstream of the registration roller pair 8 and in proximity to the registration roller pair 8.

  The flag 24 and the sensor 25 are used for the leading edge of the recording material P conveyed to the registration roller pair 8 from the cassette 5 side, the manual feed tray 18 side, or the conveyance roller pair 17 side during the image forming operation (printing operation) of the image forming apparatus 100. Is detected in front of the registration roller pair 8. The control board 15a controls the timing of image writing to the photosensitive drum 10 based on the detection signal. In other words, the flag 24 and the sensor 25 detect the leading edge of the recording material during the printing operation of the image forming apparatus and control the image writing timing.

  FIG. 9A is an enlarged view of the cartridge 30 portion in FIG. The developing device 32 includes a developing chamber 32b having a developing roller 32a as a toner carrying and conveying member that supplies the toner T to the photosensitive drum 10, and a toner chamber 32c that accommodates the toner T to be supplied to the developing chamber 32b. . The toner T in the toner chamber 32c is replenished to the developing chamber 32b side through the communication opening 32e between the toner chamber 32c and the developing chamber 32b and is supplied to the developing roller 32a by the rotation of the toner stirring and conveying paddle 32d.

  As shown in FIG. 9B, the unused new cartridge 30 has a communication opening 32e closed by a toner seal member 32f, and there is no toner T in the developing chamber 32b, and the toner chamber 32c is connected to the developing chamber 32b. The movement of the toner T is blocked. This prevents leakage of the toner T from the developing device 32 during distribution of the cartridge 30 and the image forming apparatus 100 included in the cartridge. When the cartridge 30 is used, the toner seal member 32f is opened, so that the toner T moves from the toner chamber 32c to the developing chamber 32b through the communication opening 32e.

  To open the toner seal member 32f, as shown in FIG. 12A, the toner seal member end portion 32f1 exposed to the outside from the slit hole 36a provided on the drive-side side surface 36R of the frame 34 of the cartridge 30 is used. It is done by the user picking and pulling with a finger. That is, the toner seal member 32f is pulled out and removed from the communication opening 32e to the outside of the cartridge 30 by pulling the end portion 32f1, and the communication opening 32e is opened (removal of the toner seal member 32f from the communication opening 32e). The

(Cartridge replacement method)
As the cartridge 30 is used for image formation, the toner contained in the developing device 32 is consumed. When the toner is consumed to such an extent that an image with satisfactory quality cannot be formed for the user who purchased the cartridge, the commercial value of the cartridge is lost.

  Therefore, for example, a means (not shown) for detecting the remaining amount of developer in the cartridge 30 is provided. Then, the remaining detection value on the control board 15a is compared with a preset threshold value for cartridge life warning or life warning. When the detected remaining amount value becomes smaller than the threshold value, the display panel 15c (FIG. 13) provided in the image forming apparatus 100 displays a life warning or a life warning for the cartridge. This prompts the user to prepare a cartridge for replacement, or prompts the user to replace the cartridge to maintain the quality of the output image.

  In the image forming apparatus 100 of the present embodiment, the replacement of the cartridge 30 is performed by front access by opening the opening / closing door 27 on the front side of the apparatus. The apparatus main body 100A has an opening 50 on the front side from which the cartridge 30 is inserted and removed. The open / close door 27 is centered on the hinge 27a on the lower side, as shown in FIGS. 7 and 8, from the closed position V for closing the opening 50, and from the closed position V to the front of the apparatus main body 100A as shown in FIG. It is possible to move between the open position W where it is tilted to the side and rotated to open the opening 50. When the opening / closing door 27 is opened to the open position W, the opening 50 is greatly opened, and the inside of the apparatus main body 100A can be accessed.

  As shown in FIGS. 11A and 11B, in the cartridge mounting portion 100B of the apparatus main body 100A, the driving side surface 60R and the non-driving side surface 60L have two upper and lower cartridge insertion / removal guide grooves 61R, respectively. 62R, 61L and 62L are arranged in mirror symmetry.

  On the other hand, as shown in FIG. 12, the driving side surface 36R and the non-driving side surface 36L of the frame 34 of the cartridge 30 are arranged symmetrically in the left and right two bosses 37R, 38R, 37L, 38L and cylindrical portions 39R and 39L are disposed. The cylindrical portions 39R and 39L are bearing portions on the driving side and non-driving side of the photosensitive drum 10. A driving force receiving portion 40 is provided on the driving side cylindrical portion 39R. Further, on the driving side surface 36R and the non-driving side surface 36L of the frame 34, the downward arcuate convex portions 46R and 46L are concentric with the cylindrical portions 39R and 39L and slightly larger in diameter than the diameter of the drum 10, respectively. Is provided.

  The cartridge 30 is mounted on the cartridge mounting portion 100B of the apparatus main body 100A in the following manner. The opening / closing door 27 is opened to open the opening 50 of the apparatus main body 100A (FIGS. 10 and 11). The cartridge 30 is inserted into the cartridge mounting portion 100B from the opening 50 with the cleaning device 33 side first.

  If the cartridge 30 to be inserted is a new unused cartridge (FIG. 9B), the toner seal member 32f is pulled out and removed as described above, and the communication opening 32e of the developing device 32 is removed. To open. If the cartridge 30 is provided with a photosensitive drum cover for protecting the exposed surface of the photosensitive drum 10, the cover is removed.

  The cartridge 30 has the drive-side bosses 37R and 38R along the drive-side upper guide groove 61R, and the non-drive-side bosses 37L and 38L along the non-drive-side upper guide groove 61L. 30 is inserted into the cartridge mounting portion 100B. In FIG. 12, A indicates the insertion direction of the cartridge 30 with respect to the cartridge mounting portion 100B.

  Then, the drive-side and non-drive-side cylindrical portions 39R and 39L of the cartridge 30 enter along the drive-side and non-drive-side lower guide grooves 62R and 62L, respectively. Then, when the cylindrical portions 39R and 39L abut against the positioning portions at the end portions of the lower guide grooves 62R and 62L on the driving side and the non-driving side, the insertion of the cartridge 30 is completed.

  In this state, the cartridge 30 is positioned at a position where an image can be formed in the cartridge mounting portion 100B, and the transfer roller 11 contacts the lower surface of the photosensitive drum 10 with a predetermined pressing force as will be described later. Is formed (FIG. 14). Further, the driving force receiving portion 40 disposed in the driving-side cylindrical portion 39R is opposed to the driving output portion 70 (FIG. 11 (a)) positioned at the terminal end of the driving-side lower guide groove 62R. It is in a state.

  Then, the opening / closing door 27 is moved from the open position W to the closed position V to close the opening 50. A pressing mechanism (not shown) performs a pressing operation via an interlocking mechanism (not shown) that interlocks with the closing operation of the open / close door 27, and the cartridge 30 is positioned and fixed at an image formable position in the cartridge mounting portion 100B. Further, the drive output unit 70 protrudes toward the cartridge mounting unit 100B and is coupled (coupled) to the drive force receiving unit 40 on the cartridge 30 side. In addition, an electrical contact (not shown) on the cartridge 30 side and an electrical contact (not shown) on the apparatus body side are in contact with each other and are electrically connected. As a result, the image forming apparatus 100 becomes ready for an image forming operation.

  Conversely, the cartridge 30 is removed from the cartridge mounting portion 100B of the apparatus main body 100A in the following manner. The opening / closing door 27 is moved from the closed position V to the open position W. The drive output unit 70 is retracted from the cartridge mounting unit 100B side by the interlocking mechanism interlocked with the opening operation of the opening / closing door 27, and the coupling with the driving force receiving unit 40 on the cartridge 30 side is released. Further, the positioning and fixing of the cartridge 30 to the apparatus main body 100A by the pressing mechanism is released. Further, when the opening 50 is largely opened, the developing device 32 side of the cartridge 30 mounted in the cartridge mounting portion 100B is exposed.

  Therefore, the user grasps the developing device 32 side of the cartridge 30 and pulls out and moves the cartridge 30 in the direction opposite to the insertion direction A. That is, the bosses 37R and 38R on the driving side of the cartridge 30 are along the upper guide groove 61R on the driving side, and the bosses 37L and 38L on the non-driving side are along the upper guide groove 61L on the non-driving side. 30 is pulled out from the cartridge mounting portion 100B and moved. As a result, the cartridge 30 is pulled out from the cartridge mounting portion 100B and taken out of the apparatus main body 100A.

  3 is an overhead view of the registration roller pair 8 and the transfer roller 11 in the image forming apparatus 100 of FIG. 7, FIG. 4 (a) is a left side view of the same part, and FIG. 3 (b) is a vertical right side view. .

  The registration roller pair 8 is a roller pair of an upper roller 8a and a lower roller 8b that are in contact with each other to form a nip portion. Both rollers 8a and 8b are disposed such that both left and right ends of the central shafts 8a1 and 8b1 are rotatably supported by bearings on left and right side plates (not shown) of the apparatus main body 100A. The registration roller pair 8 is rotationally driven in the recording material conveyance direction at a predetermined control timing by a driving device (not shown) in which the lower roller 8b is controlled by the control substrate 15a, and is stopped. The upper roller 8a rotates following the rotation of the lower roller 8b, and stops rotating when the lower roller 8b stops rotating.

  The transfer roller 11 is a conductive elastic roller having a metal core 11a and a conductive elastic body layer 11b concentrically and integrally formed around the metal core. The transfer roller 11 is disposed substantially parallel to the registration roller pair 8 at a predetermined interval on the downstream side of the registration roller pair 8 in the conveyance direction of the recording material P. The transfer roller 11 is disposed such that both left and right ends of the core metal 11a are rotatably supported by bearing members (transfer support members) 41L and 41R with respect to left and right side plates (not shown) of the apparatus main body 100A. Yes.

  The bearing members 41L and 41R are arranged so as to be slidable in the vertical direction with respect to the side plates, and are pushed up and biased by springs 42L and 42R. In a free state, the bearing members 41L and 41R are pushed up and moved by springs 42L and 42R to a predetermined upper limit regulating position defined by a stopper (not shown).

  That is, the transfer roller 11 can be moved in parallel in the vertical direction between the left and right side plates of the apparatus main body 100A, and is pushed up to a predetermined upper limit height position E by the springs 42L and 42R in the free state. Further, it is possible to sink and move downward from the predetermined upper limit height position E against the urging force of the springs 42L and 42R.

  As shown in FIGS. 7 and 8, when the cartridge 30 is mounted and positioned and fixed at the image forming position of the cartridge mounting portion 100B, the lower surface of the photosensitive drum 10 faces the upper surface of the transfer roller 11. The springs 42L and 42R are pressed against the urging force. Therefore, the transfer roller 11 sinks and moves from the predetermined upper limit height position E while compressing the springs 42L and 42R.

  As a result, the transfer roller 11 is brought into contact with the lower surface of the photosensitive drum 10 with a predetermined pressing force by the compression reaction force of the springs 42L and 42R to form a transfer nip portion with the photosensitive drum 10 (FIG. 14). In this state, the transfer roller 11 rotates following the rotation of the photosensitive drum 10.

  3 and 4, a is a recording material conveyance path from the conveyance roller pair 7 to the registration roller pair 8. The recording material conveyance path a includes a lower conveyance guide plate 51 that extends from the bottom to the top and curves rearward and extends substantially horizontally, a front-side vertical conveyance guide plate 52 that faces the lower conveyance guide plate 52, and And an upper conveyance guide plate (hereinafter referred to as a conveyance guide plate) 23.

  Reference numeral b denotes a recording material conveyance path that joins the manual feeding roller 20 to the recording material conveyance path a. The recording material conveyance path b includes a front-rear direction conveyance guide plate 53 and the conveyance guide plate 23 facing the conveyance guide plate 23.

  Further, a pre-transfer guide plate 54 that guides the lower surface of the recording material P conveyed from the registration roller pair 8 is disposed between the registration roller pair 8 and the transfer roller 11. A top sensor flag (hereinafter referred to as a flag) is located at the center position in the width direction of the guide plate (direction orthogonal to the recording material conveyance direction) on the lower side of the guide plate portion extending substantially horizontally of the lower conveyance guide plate 51. ) 24 and a photo sensor (hereinafter referred to as a sensor) 25 are provided.

  The sensor 25 is fixedly disposed on a non-moving support member (not shown). The flag 24 is disposed so as to be swingable about a shaft portion 24a with respect to a non-moving support member (not shown). The upper arm portion 24b of the flag 24 enters the recording material conveyance path a through a hole 51a provided in the lower conveyance guide plate 51.

  The flag 24 is urged to rotate in the clockwise direction indicated by the arrow in FIG. 4B by a torsion coil spring 24d. Due to the urging force of the spring 24d, the flag 24 is held in a state in which the upper arm portion 24b abuts against the inner surface of the transport guide plate 23 and further rotation is restricted. In the rotation posture state of the flag 24, the lower arm portion 24c of the flag 24 is in a position where the optical path of the sensor 25 is shielded ((a) and (b) of FIG. 4: the light shielding state of the sensor 25).

  When the recording material P is transported from the cassette 5 side, the manual feed tray 18 side, or the transport roller pair 17 side during the image forming operation of the image forming apparatus 100, the flag 24 is positioned in front of the registration roller pair 8 in the recording material transport path a. The upper arm portion 24b of the recording material P is kicked by the tip of the recording material P. Then, as shown in FIG. 4C, the flag 24 rotates about the shaft portion 24a against the spring 24d in the counterclockwise direction of the arrow, and the lower arm portion 24c opens the optical path of the sensor 25. To the position where the sensor 25 is to be moved (translucent state of the sensor 25).

  The control board 15a controls the timing of image writing on the photosensitive drum 10 based on a signal when the sensor 25 changes from the light shielding state to the light transmitting state. When the rear end of the recording material P passes the position of the upper arm portion 24b of the flag 24, the flag 24 returns to the rotational posture state shown in FIGS. 4A and 4B by the urging force of the spring 24d.

  On the upper surface of the conveyance guide plate 23, upward convex portions 43L and 43R are arranged on the left and right portions on the front side (guide plate 53 side: upstream in the recording material conveyance direction), respectively. Further, side plates 23aL and 23aR having shaft holes are respectively provided on the left and right portions of the rear side of the conveyance guide plate 23 (registration roller pair 8 side: downstream in the recording material conveyance direction). The left end and the right end of the central shaft 8a1 of the upper roller 8a of the registration roller pair 8 are fitted into the shaft holes of the side plates 23aL and 23aR, respectively.

  As a result, the transport guide plate 23 can be rotated around the central axis 8a1 of the upper roller 8a, and is rotated so that the second position Y in FIGS. 3 and 4 and the first position in FIGS. It is possible to move between the positions Z. In this embodiment, the transport guide plate 23 is a movable guide member that guides the recording material P downstream in the transport direction.

  The second position Y of the conveyance guide plate 23 is above the lower conveyance guide plate 51 and the front-rear direction conveyance guide plate 53 on the downstream side of the registration roller pair 8 in the recording material conveyance direction, as shown in FIGS. Opposite the predetermined. The guide plates 51 and 53 form the recording material conveyance path a and b. The conveyance guide plate 23 is received by the stoppers (spacer convex portions) 44 </ b> L and 44 </ b> R provided on the left and right sides of the upper and lower direction conveyance guide plates 53 at the second position Y. Yes. That is, the conveyance guide plate 23 is a guide member that guides the recording material P to the registration roller pair 8.

  Further, the first position Z of the conveyance guide plate 23 is such that the conveyance guide plate 23 at the second position Y passes the upper side of the upper roller 8a as shown by the arrow X1 around the central axis 8a1 in FIG. It is rotated reversely to the transfer roller 11 side. Then, as shown in FIGS. 5 and 6, the conveyance guide plate 23 is turned upside down and covers the transfer roller 11. Then, at the first position Z of the conveyance guide plate 23, the left and right convex portions 43L and 43R turned downward when the conveyance guide plate 23 is turned upside down are respectively the tops of the left and right bearing members 41L and 41R of the transfer roller 11. The relational structure is located corresponding to the surface.

  When the transport guide plate 23 is moved from the second position Y to the first position Z, the flag 24 is released from the rotation restriction by the transport guide plate 23. Therefore, the flag 24 rotates about the shaft portion 24a by a predetermined rotation angle defined by the stopper portion 51b in the clockwise direction of the arrow in FIGS. 6A and 6B by the urging force of the spring 24d. Along with this, the lower arm 24c moves to a position where the optical path of the sensor 25 is opened (the translucent state of the sensor 25).

  When the transport guide plate 23 at the first position Z is rotated as indicated by the arrow X2 about the central axis 8a1 and returned to the second position Y, the flag 24 is pushed on the inner surface of the transport guide plate 23. As a result, the rotational angle postures shown in FIGS. 4A and 4B are restored. As a result, the lower arm 24c moves to a position where the optical path of the sensor 25 is shielded (the light shielding state of the sensor 25).

  In the present embodiment, the transport guide plate 23 is always urged to rotate to the second position Y side about the central axis 8a1 by the urging force of the torsion coil springs 45L and 45R. Accordingly, the transport guide plate 23 is stably held at the second position Y in FIGS. 3 and 4 in the free state. The rotational movement of the transport guide plate 23 from the second position Y to the first position Z is performed against the rotational biasing force of the springs 45L and 45R.

(Cartridge included)
Next, the configuration of the image forming apparatus 100 according to the present exemplary embodiment when transported in a cartridge will be described in detail.

  When the cartridge 30 is mounted on the apparatus main body 00A for transporting the cartridge in a package, that is, when the cartridge 30 is inserted into the cartridge mounting portion 100B in a transported state, the opening / closing member 27 of the apparatus main body 100A is opened as shown in FIG. Open to W. Thereby, the cartridge mounting portion 100B of the apparatus main body 100A is largely opened.

  The conveyance guide plate 23 is located at the second position Y by the rotational biasing force of the springs 45L and 45R. Therefore, the conveyance guide plate 23 positioned at the second position Y is moved by the springs 45L and 45R by hand or using an appropriate tool (jig) as shown in FIGS. It is raised by rotating it in the direction of arrow X1 around the central axis 8a1 against the urging force.

  In this state, the cartridge 30 to be packaged and transported is inserted into the cartridge mounting portion 100B according to the mounting procedure described with reference to FIGS. As shown in FIG. 1C, the conveyance guide plate 23 raised up as shown in FIG. 1B is a cartridge 30 inserted into the cartridge mounting portion 100B as described above with respect to the inner surface side thereof. The front end of the cartridge frame 34 on the insertion side contacts and is received. Accordingly, the raised state of the conveyance guide plate 23 is maintained thereafter even if the tool is removed from the conveyance guide plate 23 by hand or by a tool.

  When the cartridge 30 is further inserted, the conveyance guide plate 23 is pushed by the cartridge 30 to be inserted and is reversed toward the first position Z around the central axis 8a1 against the urging force of the springs 45L and 45R. It is rotated. FIG. 1D shows a state in which the transport guide plate 23 is turned and reversed to near the first position Z. In this state, the left and right downward projections 46L and 46R of the frame body 34 of the cartridge 30 correspond to the left and right sides of the reverse side of the conveyance guide plate 23 that has been rotated in reverse, respectively. And abut.

  When the cartridge 30 is further inserted and the cylindrical portions 39R and 39L abut against the positioning portions at the end portions of the lower guide grooves 62R and 62L on the driving side and the non-driving side, the insertion of the cartridge 30 is completed. FIG. 2A shows a state in which the cartridge 30 is completely inserted. When the cartridge insertion is completed, the conveyance guide plate 23 is sufficiently pushed downward by the downward convex portions 46L and 46R of the left and right portions of the frame body 34 of the cartridge 30 and moved to the first position Z. .

  In this state, the left and right convex portions 43L and 43R turned downward when the conveyance guide plate 23 is turned over are in contact with the top surfaces of the left and right bearing members 41L and 41R of the transfer roller 11, respectively. The left and right bearing members 41L and 41R move downward by a predetermined amount against the urging force of the springs 42L and 42R by the pressing force of the convex portions 43L and 43R, respectively. That is, the transfer roller 11 is moved downward by a predetermined amount from the above-described predetermined upper limit height position E and held in a state of being separated from the photosensitive drum 10 on the cartridge 30 side.

  In other words, the conveyance guide plate 23 that has been reversed and moved to the first position Z comes into contact with the downward convex portions 46 </ b> L and 46 </ b> R provided on the frame body 34 of the cartridge 30. Further, the downward convex portions 43L and 43R on the side conveyance guide plate 23 abut against the bearing members 41L and 41R of the transfer roller 11.

  As described above, the conveyance guide plate 23 and the convex portions 46L and 46R provided on the frame body 34 of the cartridge 30 come into contact with each other, so that the photosensitive drum 10 and the conveyance guide plate 23 are in contact with each other as shown in FIG. It is possible to reliably provide the gap α between the two. Further, since the convex portions 43L and 43R of the conveyance guide plate 23 and the bearing members 41L and 41R of the transfer roller 11 are in contact with each other, it is possible to reliably provide the gap β between the conveyance guide plate 23 and the transfer roller 11. Become.

  The protrusions 43L and 43R of the transport guide plate 23 abut on the bearing members 41L and 41R of the transfer roller 11, so that the springs 42L and 42R are further compressed than when the transfer roller 11 abuts on the photosensitive drum 10 (FIG. 14). Is done. As a result, as shown in FIG. 2B, the transfer roller 11 moves to the retracted position, which is a transport mode position that does not contact the photosensitive drum 10 and the conveyance guide plate 23.

  Then, the opening / closing door 27 is moved from the open position W to the closed position V to close the opening 50. By closing the opening / closing door 27, the pressing mechanism performs the pressing operation as described above, and the cartridge 30 is positioned and fixed at the image forming position in the cartridge mounting portion 100B. In addition, the drive output unit 70 protrudes toward the cartridge mounting unit 100B and is coupled to the drive force receiving unit 40 on the cartridge 30 side. Further, the electrical contact on the cartridge 30 side and the electrical contact on the apparatus main body side are in contact with each other and are conducted. In this state, the image forming apparatus 100 is transported in a form in which the cartridge 30 is enclosed.

  In the image forming apparatus 100 in which the cartridge 30 is bundled as described above, the conveyance guide plate 23 is in contact with the convex portions 46L and 46R provided on the frame body 34 of the cartridge 30. Further, the convex portions 43L and 43R of the conveyance guide plate 23 are in contact with the bearing members 41L and 41R of the transfer roller 11. As a result, the transfer roller 11 is separated from the photosensitive drum 10. The conveyance guide plate 23 does not contact the transfer roller 11 and the photosensitive drum 10. Therefore, the concave portion of the transfer roller 11 is not formed or the photosensitive drum 10 is not damaged when the image forming apparatus 100 is transported together with the cartridge.

  Next, a procedure when the user first uses the image forming apparatus 100 in which the cartridge 30 is bundled as described above will be described. The user opens the opening / closing door 27 from the closed position V to the open position W to greatly open the opening 50 of the apparatus main body 100A. Then, as described above, the drive output unit 70 is retracted from the cartridge mounting unit 100B side by the interlocking mechanism interlocked with the opening operation of the opening / closing door 27, and the coupling with the driving force receiving unit 40 on the cartridge 30 side is released. The Further, the positioning and fixing of the cartridge 30 to the apparatus main body 100A by the pressing operation of the pressing mechanism is released.

  As a result, the enclosed cartridge 30 can be taken out. Therefore, the user once takes out the enclosed cartridge 30 from the apparatus main body 100.

  Here, when the power is supplied to the image forming apparatus 100 without taking out the enclosed cartridge 30, the sensor 25 is not shown in the figure because the conveyance guide plate 23 is located at the first position Z. As shown in FIG. For this purpose, the sensor 25-light transmission state signal is input to the control board 15a. Based on the input signal, the control board 15a displays on the display panel 15c to prompt the user to once remove the bundled cartridge 30 from the apparatus main body 100.

  The conveyance guide plate 23 located at the first position Z moves inside the cartridge mounting portion 100B around the center shafts 8a1 and 8b1 by the urging force of the springs 45L and 45R as the cartridge 30 is taken out. Automatically rotate to the second position Y side. That is, the transport guide plate 23 automatically moves to the second position Y when the cartridge 30 is taken out from the cartridge mounting portion 100B. Even when the conveyance guide plate 23 is pivotally moved from the first position Z to the second position Y, the conveyance guide plate 23 does not come into contact with the transfer roller 11 and the photosensitive drum 10 and is not damaged. Absent.

  As the cartridge is taken out, the transport guide plate 23 finally moves to the second position Y received by the stoppers 44L and 44R as shown in FIGS. 3 and 4 (a) and 4 (b). Held. That is, the conveyance guide plate 23 guides the recording material P conveyed from the cassette 5 side, the manual feed tray 18 side, or the conveyance roller pair 17 side to the registration roller pair 8 during the printing operation of the image forming apparatus. Is moved and held at the second position Y, which is a position for forming.

  When the conveyance guide plate 23 is moved and held at the second position Y, the flag 24 is restricted by the conveyance guide plate 23 as shown in FIGS. 4A and 4B, and the sensor 25 is shielded from light. It becomes a state. Thereafter, when the image forming apparatus 100 is turned on, or when the image forming apparatus 100 is already turned on, the sensor 25-a light shielding state signal is input to the control board 15a. The control board 15a detects that the conveyance guide plate 23 exists at the second position Y based on the input signal.

  That is, the sensor 25 detects the transport state in which the transport guide plate 23 is at the first position W as the first detection state by the flag 24, and determines that the transport guide plate 23 is in the second position Y. It is detected as the detection state.

  Further, the transfer roller 11 is brought into a free state when the cartridge 30 is taken out and the conveyance guide plate 23 is moved from the first position Z to the second position Y. Therefore, the transfer roller 11 is pushed up and moved to the predetermined upper limit height position E (FIGS. 3 and 4 (a) and (b)) by the urging force of the springs 42L and 42R.

  The user pulls out and removes the toner seal member 32f (FIG. 12A) from the new cartridge 30 that has been taken out, and opens the communication opening 32e of the developing device 32. If the cartridge 30 is provided with a photosensitive drum cover for protecting the exposed surface of the photosensitive drum 10, the cover is removed. Then, the cartridge 30 is again inserted into the cartridge mounting portion 100B of the apparatus main body 100A. At this time, the conveyance guide plate 23 remains held at the second position Y, and the cartridge 30 is inserted into the image formable position.

  When the cartridge 30 is reinserted, the lower surface of the photosensitive drum 10 on the cartridge 30 side comes into contact with and presses the upper surface of the transfer roller 11, and the transfer roller 11 is biased by the springs 41L and 41R from a predetermined upper limit height position E. Move against the sink. The upper surface of the transfer roller 11 is pressed against the lower surface of the photosensitive drum 10 with a predetermined pressing force by the compression reaction force of the springs 41L and 41R accompanying the sinking movement. As a result, a transfer nip is formed between the photosensitive drum 10 and the transfer roller 11 (FIG. 14).

  Then, the opening / closing door 27 is moved from the open position W to the closed position V to close the opening 50. The interlocking mechanism interlocking with the closing operation of the opening / closing door 27 causes the pressing mechanism to perform the pressing operation, and the cartridge 30 is positioned and fixed at the image forming position in the cartridge mounting portion 100B. In addition, the drive output unit 70 protrudes toward the cartridge mounting unit 100B and is coupled to the drive force receiving unit 40 on the cartridge 30 side. Further, the electrical contact on the cartridge 30 side and the electrical contact on the apparatus main body side are in contact with each other and are conducted. As a result, the image forming apparatus 100 becomes ready for an image forming operation.

  In this embodiment, the conveyance guide plate 23 that guides the recording material P to the registration roller pair 8 during the printing operation of the image forming apparatus 100 is used as a member that separates the transfer roller 11 from the photosensitive drum 10 when the cartridge is shipped together. Use. Thus, it is possible to separate the photosensitive drum 10 and the transfer roller 11 at the time of transportation with the cartridge in a simple configuration without requiring a dedicated component such as a separation member.

  Further, as described above, in the present embodiment, the transport guide plate 23 is at the first position Z by the top sensor flag 24 and the photo sensor 25 that detect the leading edge of the recording material P and control the timing of image writing. Something is detected. The top sensor flag 24 and the photosensor 25 detect that the cartridge 30 is new. This makes it possible to:

  When it is detected that the first position Z is a new product, the cartridge 30 is displayed on the display panel 15c so as to be removed from the apparatus main body 100A. Accordingly, when the image forming apparatus 100 enclosed with the cartridge is used for the first time, the user can recognize that the enclosed cartridge 30 is once taken out from the apparatus main body 100A.

  When the user removes the enclosed cartridge 30 from the apparatus main body 100 </ b> A, the conveyance guide plate 23 moves to the second position Y that guides the recording material P to the registration roller pair 8. Next, since the image can be formed by reinserting the cartridge 30 after the toner seal member 32f is removed, a dedicated separation member is not required.

  Furthermore, since an operation for removing the separation member and an operation for switching the switching member do not occur, the apparatus can be simplified, and an image forming apparatus with excellent operability can be provided.

  Further, when the recording material P jams in the vicinity of the registration roller pair 8 part, the conveyance guide plate 23 lifts the handle part (not shown) and rotates against the biasing force of the springs 45L and 45R around the registration roller 8a. Let Thereby, it is possible to open the recording material conveyance paths a and b upstream of the registration roller pair 8 in the recording material conveyance direction, and to remove the jammed recording material. That is, the conveyance guide plate 23 is configured to be able to open the recording material conveyance paths a and b.

  After the jam processing, the conveyance guide plate 23 is released from the handle portion, and returns to the second position Y that is received by being abutted against the stopper portions 44L and 44R by the urging force of the springs 45L and 45R. Is held.

  Further, even when the image forming apparatus 100 is used and not used for a long period of time, the user rotates the conveyance guide plate 23 to the first position Z and inserts the cartridge 30 so that the transfer roller 11 and the photosensitive roller can be easily exposed. The drum 10 can be separated. As a result, it is possible to prevent the formation of a recess due to the contact of the transfer roller 11 with the photosensitive drum 10 in a long-term rotation stop state, thereby preventing image defects.

  Here, the operation of the conveyance guide plate 23 as the characteristic guide member is summarized as follows. The conveyance guide plate 23 can take a first position W that separates the photosensitive drum 10 and the transfer roller 11 when the cartridge 30 is inserted into the cartridge mounting portion 100B. Further, when the cartridge 30 is inserted into the cartridge mounting portion 100B, the photosensitive drum 10 and the transfer roller 11 are allowed to contact each other, and a second position Y for guiding the recording material P to the downstream side in the transport direction can be taken. .

  The image forming apparatus 1 further includes transfer support members 41L and 41R that support the transfer roller 11, and the conveyance guide plate 23 is brought into contact with the transfer support members 41L and 41R at the first position W so that the transfer roller 11 is moved. Separated from the photosensitive drum 10. The transport guide plate 23 automatically moves to the second position Y when the cartridge 30 is removed from the cartridge mounting portion 100B.

[Example 2]
A mechanism for moving the conveyance guide plate 23 serving also as the separation member from the second position Y to the first position W and vice versa is a reverse rotation mechanism centered on the registration roller 8a as in the first embodiment. The present invention is not limited to this, and any means mechanism can be adopted. The second embodiment shows other means mechanisms. Constituent members / portions common to the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The configuration of the present embodiment is such that the movement region in the apparatus main body when the conveyance guide plate 23 moves from the second position Y to the first position W, and conversely from the first position W to the second position Y is as follows. Effective when narrow. In the second embodiment, the left and right convex portions 43L and 43R of the conveyance guide plate 23 are disposed downward on the left and right portions on the inner surface side of the conveyance guide plate 23.

  Then, the conveyance guide plate 23 at the second position Y as shown in FIG. 15 (a) passes over the registration roller pair 8 as shown in (b), and the first position as shown in (c). The slide can be moved without being reversed to W. X3 indicates the slide movement locus of the conveyance guide plate 23. Further, as shown in (c), the conveyance guide plate 23 at the first position W follows the slide movement locus X3 in reverse, and passes over the registration roller pair 8 as shown in (b). Thus, the slide movement to the first position W is possible.

  Here, although a specific means mechanism for sliding the conveyance guide plate 23 without being reversed as described above is omitted in the drawing, an appropriate means mechanism can be adopted. For example, a mechanism configuration is adopted in which guide rails or guide grooves are provided on the left and right side plates of the apparatus main body 100A, and sliders (guided members) guided by the rails or grooves are provided on the conveyance guide plate 23 side. I can do it. Also, a link mechanism configuration can be adopted.

  In the present embodiment, the conveyance guide plate 23 is constantly urged by the urging member in the direction of sliding to the second position Y. Accordingly, in the free state, the transport guide plate 23 is held at the second position Y where it is received by the stoppers 44L and 44R (FIG. 15A). In the second position Y, the conveyance guide plate 23 is opposed to the lower conveyance guide plate 51 and the front-rear direction conveyance guide plate 53 in a predetermined manner similarly to the conveyance guide plate 23 of the first embodiment, and the recording material conveyance path a and b is formed.

  Further, the conveyance guide plate 23 held at the second position Y regulates the rotation angle of the flag 24 in the same manner as the conveyance guide plate 23 of the first embodiment. Thereby, the sensor 25 is in a light shielding state.

  As the conveyance guide plate 23 is slid from the second position Y to the first position W, the rotation angle restriction of the flag 24 is released and the sensor 25 is transparent as in the case of the first embodiment. The light state is obtained (FIGS. 15B and 15C). Further, in the state where the conveyance guide plate 23 is slid to the first position W, the left and right convex portions 43L and 43R on the inner surface side of the conveyance guide plate 23 are respectively left and right bearing members 41L and 41L of the transfer roller 11. It has a relational configuration located corresponding to the top surface of 41R.

  When the cartridge 30 is mounted on the apparatus main body 00A for cartridge-enclosed transportation, the opening / closing door 27 of the apparatus main body 100A is opened to open the opening 50 as in the first embodiment. As shown in FIGS. 15A to 15B, the conveyance guide plate 23 positioned at the second position Y is placed on the upper portion of the registration roller pair 8 by hand or using an appropriate tool. Slide against the biasing force.

  In this state, the cartridge 30 to be shipped in a bundle is inserted into the cartridge mounting portion 100B according to the mounting procedure described with reference to FIGS. Then, as shown in FIG. 16A, the downward projections 41 </ b> L and 41 </ b> R of the left and right portions of the cartridge 30 come into contact with the left and right portions of the upper surface of the conveyance guide plate 23. Therefore, after that, even if the tool is released from the transport guide plate 23 by hand or the tool is released, the slide movement state of FIG. When the cartridge 30 is further inserted, the transport guide plate 23 is pushed by the inserted cartridge 30 and is slid toward the first position Z against the urging force.

  When the cartridge 30 is further inserted and the cylindrical portions 39R and 39L abut against the positioning portions at the end portions of the lower guide grooves 62R and 62L on the driving side and the non-driving side, respectively, the insertion of the cartridge 30 is performed as in the first embodiment. Is completed. When the cartridge 30 is completely inserted, the conveyance guide plate 23 is moved further to the first position Z by being sufficiently pushed downward by the downward convex portions 46L and 46R of the left and right portions of the frame body 34 of the cartridge 30. It becomes a state. The left and right bearing members 41L and 41R move downward by a predetermined amount against the urging force of the springs 42L and 42R by the pressing force of the convex portions 43L and 43R, respectively.

  That is, the transfer roller 11 is moved downward by a predetermined amount from the above-described predetermined upper limit height position E and held in a state of being separated from the photosensitive drum 10 on the cartridge 30 side. Thus, as in the case of the first embodiment, the conveyance guide plate 23 that has been slid to the first position Z comes into contact with the downward convex portions 46 </ b> L and 46 </ b> R provided on the frame body 34 of the cartridge 30. Further, the downward convex portions 43L and 43R on the side conveyance guide plate 23 abut against the bearing members 41L and 41R of the transfer roller 11.

  Since the conveyance guide plate 23 and the convex portions 46L and 46R provided on the frame body 34 of the cartridge 30 are in contact with each other, as in the case of the first embodiment, as shown in FIG. It is possible to reliably provide the gap α between the plate 23. Further, since the convex portions 43L and 43R of the conveyance guide plate 23 and the bearing members 41L and 41R of the transfer roller 11 are in contact with each other, it is possible to reliably provide the gap β between the conveyance guide plate 23 and the transfer roller 11. Become.

  Then, the opening / closing door 27 is moved from the open position W to the closed position V to close the opening 50. By closing the opening / closing door 27, as in the case of the first embodiment, the pressing mechanism performs a pressing operation, and the cartridge 30 is positioned and fixed at the image forming position in the cartridge mounting portion 100B. In addition, the drive output unit 70 protrudes toward the cartridge mounting unit 100B and is coupled to the drive force receiving unit 40 on the cartridge 30 side. Further, the electrical contact on the cartridge 30 side and the electrical contact on the apparatus main body side are in contact with each other and are conducted. In this state, the image forming apparatus 100 is transported in a form in which the cartridge 30 is enclosed.

  The procedure when the user first uses the image forming apparatus 100 in which the cartridge 30 is bundled as described above is the same as that in the first embodiment. In the case of the second embodiment, the conveyance guide plate 23 slides from the first position W to the second position Y by the urging force of the urging member as the cartridge 30 is taken out.

  The image forming apparatus according to the present embodiment also has the same function and effect as described in the image forming apparatus according to the first embodiment, and a description thereof will not be repeated.

[Other matters]
(1) The image forming apparatus is not limited to an electrophotographic apparatus. It may be an electrostatic recording type image forming apparatus using an electrostatic recording dielectric as an image carrier, or a magnetic recording type image forming apparatus using a magnetic recording magnetic body as an image carrier.

  (2) The image forming apparatus may be configured such that the transfer unit contacts the image carrier via a recording material conveying member or an intermediate transfer member.

  (3) The cartridge has at least an image carrier. A so-called integrated process cartridge having an image carrier and at least developing means as image forming process means acting on the image carrier is included. A so-called separation type process cartridge having an image carrier and at least one process means other than a developing means as an image forming process means acting on the image carrier is also included.

  100..Image forming apparatus, 100A..Main body, 100B..Cartridge mounting portion, 30..Cartridge, 10..Image carrier, P..Recording material, 11..Transfer means, 41L.41R..Transfer Supporting member, 8 ... Transport means, 23 ... Guide member, W ... First position, Y ... Second position

Claims (10)

An image forming apparatus for forming an image on a recording material, wherein a cartridge having at least an image carrier on which a toner image is formed is detachable from an apparatus main body,
A cartridge mounting portion on which the cartridge is detachably mounted;
A transfer device that contacts the image carrier and forms a nip for transferring a toner image formed on the image carrier to a recording material;
A transport mechanism for transporting the recording material to the nip portion;
A movable guide member for guiding the recording material downstream in the transport direction;
The guide member includes a first position that separates the image carrier and the transfer device when the cartridge is inserted into the cartridge mounting portion, and the guide member when the cartridge is inserted into the cartridge mounting portion. A second position for allowing the image carrier and the transfer device to contact each other and guiding the recording material downstream in the transport direction ;
The image forming apparatus , wherein the guide member is located between the transfer device and the cartridge and covers the transfer device when in the first position . The image forming apparatus further includes a transfer support member that supports the transfer device ,
2. The image forming apparatus according to claim 1, wherein the guide member is in contact with the transfer support member at the first position to separate the transfer device from the image carrier. 3.   The image forming apparatus according to claim 1, wherein the guide member automatically moves to the second position when the cartridge is taken out from the cartridge mounting portion. The image forming apparatus according to claim 1, wherein the guide member is a guide member that guides a recording material to the transport mechanism .   A detection flag that abuts on the guide member and is rotatable; and a detection sensor that detects a position of the detection flag. The sensor is configured to transport the guide member at the first position by the detection flag. 5. The image formation according to claim 1, wherein the state is detected as a first detection state, and the second detection state is detected as the second position of the guide member. apparatus.   The image forming apparatus according to claim 5, wherein the detection flag and the detection sensor detect a leading end of a recording material and control an image writing timing during a printing operation of the image forming apparatus.   The image forming apparatus according to claim 1, wherein the guide member is configured to be able to open a recording material conveyance path. The image forming apparatus according to claim 2, wherein the transfer support member is urged to move in a direction in which the transfer device is brought into contact with the image carrier. 9. The image forming apparatus according to claim 1, wherein the cartridge is a process cartridge including the image carrier and an image forming process device that acts on the image carrier.   The image forming apparatus according to claim 1, wherein the image carrier is an electrophotographic photosensitive drum.